Real-world Performance of Clinical MRI Faraday Cages

Motivation: There is a general lack of understanding of real-world MRI Faraday cage performance. Goal(s): Survey the attenuation of Faraday cages when MR systems first become operational and assess how Faraday cage performance varies over time. Approach: Faraday cage attenuation measurements were acquired as part of new MRI scanner acceptance testing & from existing MRI systems of varying ages between 1-15 years. Results: The median Faraday cage attenuation at all locations at acceptance testing met the IEEE specification up to 128MHz, however 16/37 scanners had at least one measurement below 80dB at its' resonant frequency. Impact: This work shows that having an independent check of RF cage performance after scanner installation can be helpful if Faraday cage attenuation has been reduced during the installation process.